My wife and I recently moved our phones to Virgin, because it's cheaper and uses the same carrier as the expensive service we were paying for. I live in a rural area and service sucks so I want to enable wifi calling so I can make and receive calls at home. I've been trying for a couple of days and it keeps failing with this error message. My wife decided to try, just in case it was some issue with my phone, and she rushed through and accepted everything, including the consent to collecting data for advertising that I had declined - hers worked straight away! Now I don't want to try consenting to find out if that's why mine won't work because I'm in the mood for a fight with them. I know I won't win, but I'm curious to see where it goes.
EDIT: I chatted with their agent for a few seconds - it was fairly easy to convince it to connect me to a human. The human was happy to manually enable WiFi calling for me in the back end. I still believe this is nasty behavior - they're trying to get people to go back and try again, and maybe consent to data collection next time around.
If their ToS is unacceptable to you, I guess you could get VoIP service from a SIP provider and just always use VoIP via a VoIP app rather than your phone's native calling support. Just use your telco for data.
Costs more.
I think that it'd be mostly of interest if you really wanted privacy, since you could run the VoIP to a VPN provider, and then the VoIP provider doesn't know where you are physically and your telco knows where you are but has no idea what you're doing (other than talking to your VPN provider).
Plus, while your options are limited as to telcos
there's a natural monopoly from owning the physical infrastructure for a vell netwoek
you have lots of options for VoIP service providers.
In the US, I believe that there may be some (recently-added) restrictions on SIP SMSing.
EDIT: One other thought. If you and your wife have different phone hardware and especially if your hardware is very old, I believe that there's hardware support required for WiFi calling support.
searches
Yeah, sounds like it.
https://www.att.com/features/wifi-calling/
It's possible that that's what you're hitting.
My phone is actually newer. I know wifi calling works on my phone because I had it enabled with our previous carrier.